CA2590022A1

CA2590022A1 - Channel estimator with extended channel bandwidth

Info

Publication number: CA2590022A1
Application number: CA002590022A
Authority: CA
Inventors: Michael M. Wang; Rajeev Agrawal; Tyler A. Brown; Xiangyang Chen; Ajoy K. Singh
Original assignee: Individual
Current assignee: Motorola Solutions Inc
Priority date: 2004-12-16
Filing date: 2005-11-17
Publication date: 2006-06-22
Anticipated expiration: 2025-11-17
Also published as: EP1829261A4; CN101076964B; WO2006065434A3; CN101076964A; EP1829261A2; CA2590022C; WO2006065434A2; US7573964B2; US20060133457A1

Abstract

A method (1700) and apparatus (1801) provide channel estimation with extended bandwidth filters. Antenna (1813) receives a signal such as a pilot signal and detects a bandwidth associated with the pilot signal in a detector (320). One of a plurality of filters (603, 605, 607, and 609) including extended bandwidth filters (311) and a default filter (305) can be selected by a selector (617). If the detector detects activity associated with a wider bandwidth, the filter associated with the wider bandwidth is selected over the presently selected filter. If no activity is detected, the default filter is selected.

Claims

1. A method for providing an estimation of a channel in a receiver associated with one or more of a mobile station and a base station in a Radio Access Network (RAN), the receiver capable of moving relative to a source of a signal in accordance with a relative speed, the method comprising:

detecting the signal within one of a plurality of frequency bandwidths associated with a corresponding plurality of filters to provide a detected one of the plurality of frequency bandwidths; and selecting one of the plurality of filters for providing the estimation based on the detected one of the plurality of frequency bandwidths, wherein if the detecting the signal fails to provide the detected one of the plurality of frequency bandwidths, the selecting selects a default one of the plurality of filters for the providing the estimation.

2. A method in accordance with claim 1, wherein the detecting includes:
coherently accumulating a difference signal generated from at least two outputs of at least two of the plurality of filters;

estimating a noise variance associated with the signal; and generating a positive detection result based on the coherently accumulating the difference signal, the estimating the noise variance, and a detection threshold.

3. A method in accordance with claim 2, wherein the detecting further includes repeating the coherently accumulating the difference signal, the estimating the noise variance, and the generating the positive detection result for each of the plurality of frequency bandwidths.

4. An apparatus for providing an estimation of a channel in a receiver associated with one or more of a mobile station and a base station in a Radio Access Network (RAN), the receiver capable of moving relative to a source of a signal in accordance with a relative speed, the apparatus comprising:

a memory;

an RF interface arranged to couple to the RAN and configured to receive the signal; and a processor coupled to the memory and the RF interface, the processor configured to facilitate:

detecting the signal received from the RF interface within an associated frequency bandwidth to form a detected signal; and selecting one of a plurality of filters configured in the processor for providing the estimation based on the detected signal, wherein if the detecting fails to detect the signal within the associated frequency bandwidth, the selecting selects a default one of the plurality of filters for the providing the estimation.

5. An apparatus in accordance with claim 4, wherein the processor, in detecting the signal within the associated frequency bandwidth is further configured to:

generate a difference signal between at least two outputs associated with at least two of the plurality of filters;

coherently accumulate the difference signal during a time interval;
estimate a noise variance associated with the signal during the time interval; and generate a positive detection result based on the coherently accumulating the detection threshold, the estimating the noise variance, and a detection threshold.

6. A channel estimator configured for estimating a channel in a receiver associated with one or more of a mobile station and a base station in a Radio Access Network (RAN), the receiver capable of moving relative to a source of a signal in accordance with a relative speed, the channel estimator comprising:

a default filter and an extended filter;

a detector configured to receive the signal and detect channel activity associated with the signal to form a detected channel activity, the detected channel activity capable of being detected in connection with a bandwidth associated with one of the default filter and the extended filter; and a selector coupled to the default filter, the extended filter, and the detector, the selector configured to select one of the default filter and the extended filter based on the detected channel activity to provide the estimating the channel.

7. A channel estimator in accordance with claim 6, wherein if the detector does not detect channel activity, the selector selects the default filter to provide the estimating the channel.

8. A channel estimator in accordance with claim 6, further comprising one or more additional extended filters.

9. A channel estimator in accordance with claim 8, wherein the detector is further configured such that the detected channel activity is capable of being detected in connection with an additional bandwidth associated with one of the one or more additional extended filters.

10. A channel estimator in accordance with claim 8, wherein the selector is further coupled to the one or more additional extended filters and is further configured select one of the one or more additional extended filters based on the detected channel activity to provide the estimating the channel.